////#define _CRT_SECURE_NO_WARNINGS 1
////#include<stdio.h>
////#include<string.h>
////#include<ctype.h>
////#include<errno.h>
////int main()
////{
////	char arr[] = "aBCd@ef.Gh";
////	char* p = "@.";
////	char* ret;
////	int i = 0;
////	while (arr[i])
////	{
////		if (isupper(arr[i]))
////		{
////			arr[i] = tolower(arr[i]);
////		}
////		i++;
////	}
////	printf("%s\n", arr);
////	for (ret = strtok(arr, p); ret != NULL; ret = strtok(NULL, p))
////	{
////		printf("%s\n", ret);
////	}
////	FILE* pf = fopen("text.txt", "r");
////	if (pf == NULL)
////	{
////		printf("%s\n", strerror(errno));
////	}
////	return 0;
////}